Organelles

Question 1

Non membranous organelles

Answer 1

No membrane •
Direct contact with cytosol •
Include the cytoskeleton, microvilli, centrioles, cilia,
ribosomes, and proteasomes

Question 2

Membranous organelles

Answer 2

Covered with phospholipid membrane
• Isolated from cytosol
• Include the nucleus, endoplasmic reticulum (ER), the
Golgi apparatus, lysosomes, peroxisomes, nucleus, and mitochondria

Question 3

Cilia

Answer 3

Primary cilia- has sensory function, sends signals to inside of cells
Motile cilia- moves fluids/itself

Question 4

Ribosomes

Answer 4

Build polypeptides in protein synthesis
2 types
-free ribosomes= in the cytoplasm, Manufacture proteins for the cytosol
-fixed ribosomes= in the ER, Manufacture proteins for places other than the cytosol

Question 5

Proteasomes

Answer 5

Contain enzymes (proteases) • 
Disassemble damaged proteins for recycling

Question 6

Nucleus

Answer 6

Cell control center and largest organelle
Nuclear envelope
•Double membrane around the nucleus
Perinuclear space
•Between the two layers of the nuclear envelope Nuclear pores
•Communication passages

Question 7

Contents of the nucleus

Answer 7

DNA
•All information to build and run organisms

Nucleoplasm
•Fluid containing ions, enzymes, nucleotides,
and some RNA

Nuclear matrix
•Support filaments

Nucleoli
•Are related to protein production
•Are made of RNA, enzymes, and histones
•Synthesize rRNA and ribosomal subunits

Question 8

Cisternae

Answer 8

storage chambers within membranes

Question 9

Functions of the ER

Answer 9

1) Synthesis of proteins, carbohydrates, and lipids
2) Storage of synthesized molecules and materials 3. Transport of materials within the ER
4. Detoxification of drugs or toxins

Question 10

Smooth ER

Answer 10

No ribosomes attached
• Synthesizes lipids, fatty acids, and carbohydrates
• Phospholipids and cholesterol (membranes)
• Steroid hormones (reproductive system)
• Glycerides (liver cells and fat cells)
• Glycogen (skeletal muscle and liver cells)

Question 11

Rough ER

Answer 11

Surface covered with ribosomes
• Active in protein and glycoprotein synthesis
• Folds polypeptide protein structures
• Encloses products in transport vesicles

Question 12

Golgi Aparatus

Answer 12

Vesicles enter forming face and exit maturing face
-Functions
1. Modifies and packages secretions
• Hormones or enzymes
• Released through exocytosis
2. Renews or modifies the plasma membrane
3. Packages special enzymes within vesicles for use
in the cytoplasm

Question 13

Lysosomes

Answer 13

Powerful enzyme containing vesicles
Primary-
Formed by Golgi apparatus
• Contains inactive enzymes

Secondary-
Lysosome fused with damaged organelle,
digestive enzymes activated

Question 14

Autolysis

Answer 14

Auto- = self, lysis = break 
Self-destruction of damaged cells
•Lysosome membranes break down
•Digestive enzymes released
•Cell decomposes
•Cellular materials recycle

Question 15

Peroxisomes

Answer 15

Are enzyme-containing vesicles - Peroxisomes contain at least 50 different enzymes
• Formed by endoplasmic reticulum
• Break down oxidative substrates: fatty acids, amino acids, and uric
acid
• Produce hydrogen peroxide (HO) as a product of oxidative
reactions
• contain the enzyme catalase converting hydrogen peroxide to water and
oxygen
• Invovled in lipid biosynthesis
• In liver cells involved in synthesis of bile acids